The manual transmission, also known as the gearbox, is a standard transmission. It is also called a stick shift or simply a stick, as well as the gearbox. The transmission system is used in motor vehicle applications.
A manual transmission is the oldest transmission used in automobiles to date. It uses a driver-operated clutch for engagement and disengagement via the foot pedal.
It can also be done using a hand lever along with a gear selector, which is operated by hand. This regulates torque transfer from the engine to the transmission.
The gearbox system is conventionally designed with a 5- or 6-speed manual transmission. It is standard in a modern base modern vehicle. The 5-speed types are common on commercial vehicles and lower-end vehicles.
Higher-end vehicles like luxury and sports cars feature the 6-speed transmission for the base model. There are also other transmission options available.
What is Manual Transmission?
Manual transmissions require the driver to manually change gears using a clutch pedal and a shifter. These types of transmissions consist of a set of gears along a pair of shafts, called the input and output shafts.
How does a manual transmission work? With a manual transmission, the driver must select the proper gear and engage or disengage the clutch. The transmission uses a flywheel, pressure plate and clutch to engage and disengage the engine from the transmission.
The flywheel and pressure plate are connected to the engine. The clutch is sandwiched between them and is splined to the transmission input shaft.
The act of “pushing in the clutch” releases the pressure plate, which disengages the clutch from the engine. Every time you make a shift, you have to push in the clutch first.
Types of Manual Transmission
Below are the types of manual transmissions:
Sliding-gear Transmission:
These types of manual transmissions are known as unsynchronized transmissions. It was invented in the late 19th century, which is why it is found on older models of cars.
When staying stationary when the transmission is neutral. In the transmission case, the main drive gear and cluster gear keep moving.
The clutch pedal must be pressed in order to free the shifter handle. The shifter handles change the position of the shift linkage and forks and slide a gear to the main shaft. The clutch is released once the gears have meshed.
Constant-Mesh Transmission:
These types of transmission are known as synchronized transmission. The drive gear, cluster gear, and main shaft gears are in constant motion. This happens because the gears freely spin around the main shaft. Sliding gear transmissions are used to lock gears in place.
A dog clutch also helps to lock these gears in place when needed. The teeth on the dog clutch and main shaft gears lock onto each other and hold the gear stationary. This occurs as the shift linkage moves.
The synchronizers are used in this transmission to prevent clashing or grinding while changing gears.
Preselector Manual Transmission:
This manual transmission system was also developed before the invention of automatic transmission. It is known as the Wilson preselector, introduced in 1930. The transmission uses a planetary gear system to preselect the gear ratio.
A small lever on the steering column is used. Drivers shift gears by pressing down the foot pedal, which notifies one of the preselected gears. The previous gear disengaged immediately after the new gear engaged.
Parts of the Manual Transmission System and Their Functions
Below are parts of manual transmission and their functions:
- A clutch disc: allows the torque to be transmitted from the engine to the manual transmission system. This disc works when the clutch pedal is pressed.
- The clutch pedal: is a manual transmission part that is operated hydraulically. it controls the clutch disc when pressed by hand.
- Synchronizers: synchronizers allow the engagement between the collar and the gear. It makes the speed synchronized. The speed could end up being different but it prevents that from happening.
- Flywheel: The flywheel is one of the major parts in manual transmission that sends torque from the engine to the clutch disc.
- Gears: gears in the transmission are of different sizes, big and small. The big gears generate extra torque to slow down the speed of the vehicle. Smaller gears generate less torque, making the vehicle move faster.
- Selector fork: a gear that allows the collars to move on the output shaft.
- Stick shift: this manual transmission part is used for applying the gear by hand. It is connected to the gearbox.
- Collar: collars are used to lock the selected gear in place and allow the torque to pass to the output shaft.
Gear Ratio And How They Change The Output
Before we explaining the working of a manual transmission we need to get into what are gear ratios and how they change the engine output.
Gear ratio can be explained as the ratio of teeth of the gears. In the case of transmission its the ratio of the driven gear by the driving gear. The gear ratio can help us explain how we get more torque on low gear and high speed at higher gears.
To explain why lower gear gets high torque we need to refer to the formula for torque. Torque equals force times the distance. Distance, in this case, is the radius of the driven gear. As we know the driven gear gets smaller as we go up the ratio thus we get more torque at lower gears.
As to why higher gear offers more speed, output RPM of a car is determined by the engine RPM divided by the gear ratio. Higher gears have a smaller gear ratio which allows us to get more RPM.
To explain this with an example. Imagine your RPM is constantly at 1000. Assume your first gear ratio is 3:1, this makes the output RPM as 333.3RPM. Now assume your top gear ratio is 0.5:1, this means your output RPM now will be 2000.
How Manual Transmission Works
The workings of this transmission system contain a set of gears along with a pair of shafts, which are the input and output shafts. The gears on the first shaft engage with those on the other shaft.
The ratio between the selected gear on the input shaft and the gear engaged on the output shaft determines the overall gear ratio for that gear.
Gears are engaged in a manual transmission system by moving the shift lever. The engagement is done by the linkages that control the movement of the gears along the input shaft.
Cars with four gears or speeds have two linkages and cars with five or six speeds use three linkages. This linkage changes by moving the shift lever left and right.
The clutch plays an important role in the working of the manual transmission as disconnects the engine from the input shaft of the transmission when pressed.
It frees the gears on the input shaft, causing it to easily move as the engine sends torque through the input shaft. This caused the engagement. The clutch is said to be disconnected when the clutch lever is not pressed.
Once the clutch disconnects the power from the engine to the transmission, the driver easily selects the gear and releases the clutch. Releasing the clutch allowed engine power to be reengaged to the input shaft, which makes the car move at the selected gear ratio.
How To Start a Manual Car
To start manual transmission cars, you first need to check out the floor, where the pedals are located. Unlike a car with an automatic transmission, you will notice that a manual car uses a third pedal, known as the clutch. The clutch will be the pedal on the far left.
Depress the clutch with your left foot, put the gear shifter in a neutral position, and either turn the ignition key or press the start button to get the car started.
While your left foot presses the clutch, you may also need to keep your right foot on the brake to keep the car from rolling if you’re on a hill.
Some people use the emergency brake to keep the car in place during this process, while other cars feature a hill-hold feature that momentarily keeps the vehicle from rolling.
How To Drive a Manual Car
- Shift into first gear. Press the clutch and move the gear lever into first gear.
- Ease the left foot off the clutch as the right foot presses the gas pedal. You can now completely remove your right foot from the brake or emergency brake while simultaneously removing your foot from the clutch. At the same time, use your now free right foot to press the gas pedal gently. This needs to be a smooth, seamless motion. You should feel the car start to move.
- Remove your foot from the clutch. At this point, you should remove your foot from the clutch and only press the accelerator.
- Shift into second gear. As you gain momentum, press your left foot onto the clutch again, and shift the vehicle from first to second gear. The first gear position is usually in the upper left, and shifting to second gear means moving the lever straight down. Again, release the clutch as your right foot presses the gas pedal. This will take some practice to learn how to transition seamlessly, especially when you transition.
- Repeat. You will repeat this process through all the gears to accelerate to your desired speed.
- Slowing down. To slow down a manual car, you will reverse the process, using the same method of pressing in the clutch with your left foot while downshifting. You can also simply put the car in neutral and use the brakes.
- Stopping the vehicle. When you want to stop the car completely, such as at a traffic signal, press down on the brake as you normally would. As your vehicle reaches a slow rolling stop, step onto the clutch.
- Go back to neutral. Place the car in the neutral position again. You can now lift off the clutch pedal while keeping your foot on the brake. To get moving again, repeat the steps above.
Learning when to change gears is the most important part of driving a stick, and timing it properly will help to prevent your car from stalling. This will come with practice.
But you will get the feel of it. When the car speeds up, you will feel the car engine and hear it telling you to switch to the higher gear as you drive. Same for changing to a lower gear to slow down. Some vehicles will also display an indicator when it’s time to shift.
Advantages of a Manual
Once you learn how to drive a stick shift properly, you will understand why driving purists enjoy driving them. There are multiple advantages to driving a manual. They include:
- You have ultimate control over your car. When you drive a manual, you have more control over the vehicle’s speed and handling.
- Acceleration feel. As you switch gears, you decide when the car accelerates. The acceleration can feel livelier because you can hold the gear longer than would be typical in an automatic transmission.
- Cheaper. Since these cars aren’t in high demand anymore, they tend to be cheaper to purchase than their automatic transmission counterparts.
- Makes going up or downhill a breeze. Manually changing the gear can help you get up a steep hill easier. Also, a manual puts less strain on your brakes when going downhill.